sounds like a lot of water.
I don't know where you are located but in Jersey, we are really taking alot of rain. I'd first check the watertightness of any ports and especially cockpit drain scuppers and the hoses you have attached to them- with an 80's era boat these hoses and the "sleeve" interconnects start to leak.
Thereafter, you can use baby powder or the "blue dust" sold for dusting plumb(snap) lines (see hardware store) but sometimes the lattercan be messy to get off. start under and around those hose connections.
Dust the area around the bilge and eventually higher and to the boat's outer perimeter. You should be able to see where the dust is washing out as you go outboard and up. You should find your problem spot. if you don't see any washout dust in the upper parts of the bilge- I'd start looking at what hoses feed into the bilge and look around the beginnings of those hoses.
I don't know your boat's setup - but you might also want to check the watertightness of any forward anchorlocker thru latch bolt. I found on my 28.5 a leak at that point- caulk it up with marine silicone, put some cellophane on the insert portion of the bolt/latch and push it into the caulked up "receiver" end, let dry and trim the excess cellophane and caulk.
Good luck